I write code and sharing my experiences with the world. My special interests are crypto implementation, information security and systems programming. My pronouns are they/them.

Currently I am working as a PhD student researching post-quantum cryptographic implementations at the Radboud University of Nijmegen, supervised by Peter Schwabe from MPI-SP and Joppe Bos from NXP.

Recent blog posts

• No more Disqus on this blog
• The Kyber/Dilithium NTT
• LLVM provides no side-channel resistance

Publications and technical reports

• Dilithium for Memory Constrained Devices. Joppe W. Bos, Joost Renes, Daan Sprenkels, AFRICACRYPT 2022 (to appear) [paper]
• Faster Kyber and Dilithium on the Cortex-M4 Amin Abdulrahman, Vincent Hwang, Matthias J. Kannwischer, Daan Sprenkels, ACNS 2022 (to appear) [paper]
• Don't throw your nonces out with the bathwater: Speeding up Dilithium by reusing the tail of \(\mathbf{y}\). Daan Sprenkels, Bas Westerbaan, Cryptology ePrint Archive, Report 2020/1158 [paper]
• Compact Dilithium Implementations on Cortex-M3 and Cortex-M4. Denisa O. C. Greconici, Matthias J. Kannwischer, Daan Sprenkels, IACR Transactions on Cryptographic Hardware and Embedded Systems (TCHES), 2021(1):1–24 [paper|code]
• Assembly or Optimized C for Lightweight Cryptography on RISC-V? Fabio Campos, Lars Jellema, Mauk Lemmen, Lars Müller, Daan Sprenkels, Benoit Viguier, CANS 2020: Cryptology and Network Security, LNCS, vol. 12579, pp. 526–545, Springer [paper]
• The complete cost of cofactor \(h=1\). Peter Schwabe, Daan Sprenkels, Progress in Cryptology – INDOCRYPT 2019, LNCS, vol. 11898, pp. 375–397, Springer [paper|code]
• ECC implementation on Sandy Bridge Daan Sprenkels, Master thesis [pdf|code]

Slides

• 7 November 2020 – Secret Types in Rust @ RustFest Global 2020
• 30 October 2020 – Dilithium on Cortex M3 and Cortex M4 @ DiS, Radboud University
• 18 December 2019 – The complete cost of cofactor \(h=1\) @ INDOCRYPT 2019
• 1 April 2019 – ECC implementation on Sandy Bridge @ Radboud University
• 28 December 2017 – We should share our secrets @ 34C3

Code

• Rushlink – An URL shortener/pastebin dump [go]
• MAC-Minitables – Reverting MAC address hashing [rust]
• Curve13318 – Secure ECC scalar multiplication on AVX, AVX2 and Cortex M4 [c, x86_64, armv7]
• ws2812b_attiny13 – WS2812B driver for the ATTiny13 [c, avr]
• Shamir secret sharing library – Split secrets into multiple parts [c]
• randombytes – A portable C library for generating cypto-secure random bytes [c]
• Mysterion implementation – A Cortex-M4 implementation of the Mysterion block cipher [armv7]